Sunday, April 9, 2017

BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, APRIL 9, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME

CLEAR SKIES LEAD TO WARM TEMPERATURES AND DRY CONDITIONS

With only a few cirrus clouds in the sky all day, temperatures
quickly rose into the 60’s after starting the day in the low 30’s.
The temperature at the 1 o’clock observation was 62 degrees.

Dew points remained stable as the temperature rose so the humidity
dropped quickly throughout the morning.  Relative humidity at the
1 o’clock observation was 18%.

The atmospheric pressure continued to rise today until late morning,
when the pressure leveled off. The pressure then continued to
rise by the 1 o’clock observation.

Winds were calmer than in previous days, with a peak gust of 24 mph by
early afternoon with light winds occurring at the 1 o’clock observation.
Winds, which had been out of the west southwest all morning were
shifting between west southwest and west northwest by the afternoon.

Today’s Observations:

7 A.M.
Weather: Few cirrus in all directions
Temperature: 40F; Dew Point: 24F; Wind: W at 10 kts,
Sea-level pressure: 30.06 ins. Hg, rising steadily
Visibility: 80 miles
6-hr Max temp: 40F
6-hr Min temp: 34F
24-hr precip: 0.00
24-hr snowfall: 0.0 in.
BHO SA 1155 CLR 80 178/40/24/2810/006/ FEW CI ALQDS/ 8/001 51033
10040 20034

10 A.M.
Weather: Few cirrus SSW-WNW
Temperature: 56F; Dew Point: 21F; Wind: WNW at 17 kts,
Sea-level pressure: 30.08 ins. Hg, rising, then more quickly
Visibility: 80 miles
BHO SA 1455 CLR 80 188/56/21/2910/008/ FEW CI SSW-WNW/ 8/001 51010

1 P.M.
Weather: Few Cirrus all quadrants
Temperature: 62F; Dew Point: 22F; Wind: VRB at 06 kts,
Wind: Light
Sea-level pressure: 30.08 ins. Hg, steady then rising
Visibility: 80 miles
6-hr Max temp: 47F
6-hr Min temp: 37F
6-hr precip: 0.00 in.
6-hr snowfall: 0.0 in.
BHO SA 1755 CLR 80 189/62/22/VRB06/008/ FEW CI ALQDS WND LGT/ 8/001
53001 10062 20040

SUMMARY FOR SATURDAY, APRIL 8, 2017

TEMPERATURE (DEGREES F)
MAX…..50   NORMAL…..53
MIN…..37   NORMAL…..35
MEAN….44   NORMAL…..44

DEPARTURE FROM 30-YEAR NORMAL……………………..0
TOTAL DEPARTURE FOR THE MONTH…………………….-4 [-0.7 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..21   DEPARTURE………..0
TOTAL HEATING UNITS FOR THE MONTH………….185   DEPARTURE……….+4
TOTAL HEATING UNITS FOR THE SEASON………..5087   DEPARTURE……..-578
TOTAL HEATING UNITS LAST SEASON TO DATE……4602   DIFFERENCE…….+461

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….37 WNW AT 10:12 A.M.
AERO……………………39 WNW AT 11:52 A.M.*
ASOS……………………38 WNW AT 10:11 A.M.
DAVIS…………………..37 NW  AT 10:11 A.M. RMY 39
FASTEST MILE FOR YESTERDAY…………………24 WNW AT  1:59 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………26 WNW AT  3:02 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..26 NW  AT  7:23 A.M.
AVERAGE WIND SPEED AND DIRECTION………….16.5 WNW
ASOS………………….16.1
DAVIS…………………15.0 NW [315 deg.] *Last of multiple occurrences

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE……-0.16
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….4.26  DEPARTURE……+2.91
ASOS…………..4.27
TOTAL PRECIPITATION FOR THE YEAR……….18.38  DEPARTURE……+3.03
ASOS……………N/A ***
*** ASOS annual total not available due to erroneous readings

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE…….-0.2
TOTAL SNOWFALL FOR THE MONTH…………….2.7  DEPARTURE…….+1.3
TOTAL SNOWFALL FOR THE SEASON…………..66.4  DEPARTURE…….+5.3

PRELIMINARY CLIMATE SUMMARY FOR APRIL CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/PEAK GUST/AERO/RMY GUST
AERO: Aerovane wind recording system gust
RMY:  R.M. Young wind gust recording system
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized
M:    Missing data

4/1  35/31/33/-8/2.21/2.7/000/00           40 ENE AERO 41 ENE RMY 41
4/2  53/30/42/+1/0.00/0.0/…/..           32 NW  AERO 33 NW  RMY 34
4/3  60/35/48/+6/0.00/0.0/…/..           21 W*  AERO 20 NW  RMY N/A
4/4  42/35/39/-3/0.78/0.0/…/..           41 ESE AERO 43 ESE RMY 42
4/5  41/35/38/-5/0.00/0.0/000/00           21 NNW AERO 20 NNW RMY N/A
4/6  55/35/45/+2/…/0.0/000/00            35 SSE AERO 37 S   RMY 37  TSTM
4/7  53/38/46/+3/…/0.0/…/..            43 SSW AERO 47 SSW RMY 48
4/8  50/37/44/0/0.00/0.0/…/..            37 WNW AERO 39 WNW RMY 39

4/9  Low temp since midnight is 34F; normal low is now 35F

DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):

RECORDS FOR APRIL 9
HIGH 83 IN 1991
LOW 18 IN 1888
PRECIP 2.38 IN. IN 1935
SNOWFALL 11.0 IN. IN 1917
PEAK GUST 72 MPH WNW IN 1962

RECORDS FOR APRIL 10
HIGH 83 IN 1922
LOW 20 IN 1985
PRECIP 2.40 IN. IN 1935
SNOWFALL 10.1 IN. IN 1996
PEAK GUST 66 MPH WNW IN 1967

TODAY’S REPORT PREPARED BY: Robert Millette